Method and apparatus for identifying the source of a digital signal
US6526035B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 9, 1998 |
| Grant date | Feb 25, 2003 |
| Priority date | — |
| Expiry date | Jun 9, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B7/2628
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A receiver can identify the source of a signal from an unsynchronized source. The receiver has an antenna for receiving two signals. The receiver correlates the first signal with a code to find a first location in time, and correlates the second signal with the same code to find a second location in time. The receiver calculates a time difference between the first location in time and the second location in time and uses the time difference to identify the source of the two signals. A group of base stations or directional antennas use the same long code and synchronization codes. However, each source shifts the long code by a different amount so that for any two sources there is a unique difference between the shifts in the long code. Each source shifts a set of synchronization codes the same amount as the long code. The synchronization codes can be any short code that is relatively easy for the mobile station to detect. When the receiver receives the two signals, the receiver calculates the difference in the shifts. Because there is a unique difference for each pair of sources, the receiver can identify the source of a signal from an unsynchronized source without having to connect…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.